The few design the future. The rest of us inherit it.

Governments, developers, insurers and investors can hire specialists to model what happens next. The future is being computed. Just not for you. Hearings, budgets, permits, insurance rates and investment decisions all depend on somebody's model of the place where you live. Everyone else gets three minutes at a microphone to react.

Whathappensify is digital public infrastructure that brings simulation to people who have never had access to it. With the same means, you can answer a plan with a better one, or start something of your own. Open a shop. Test a delivery service before you hire a driver. Change how a clinic or a market works. Make your neighborhood work better.

See how it works · Explore what you could do

Same ambulance journey.
What changes when nearby roads flood?

Without floodWith flood

Play the recorded comparison with the controls.

Without flood
212 s · 3:32
With flood
946 s · 15:46
Additional journey time
734 s · 12:14
Open comparison at full size
A test run on a real New York road network with made-up morning traffic. The same ambulance makes the same trip twice; in the second, a flood 2,000 feet across lies on the route and closes every street it touches. It shows how the model behaves, not what would happen on these streets. How this run was built

People decide questions like these all the time.

Running a business: where to park the truck today, whether to open on Sundays, which of two sites for the second shop, how far to deliver, what the lunch crowd does when the offices across the street go half-remote.

Living in a place: which apartment keeps the school run short once the new tower opens, how hot the playground gets in a heat wave, whether the basement floods again, when to leave before the storm.

Running a town or a service: the bus every twenty minutes or every forty, where the vaccine van goes this Saturday, which market day reaches the families who need it.

Most of these are decided by guesswork, because the tools that could answer them were built for organizations with specialists. In the United States alone, 36 million small businesses make decisions like the first row, and about 40 million people, 12 percent of the country, moved in the past year. Together, such questions could make asking what would happen as ordinary as checking the weather.

Small businesses: SBA Office of Advocacy, 2026. Movers: U.S. Census Bureau, American Community Survey, 2024.

Start with a question of your own

The start page: a box that reads "What would happen if…" with an Ask button, and the simulations already started listed below it as cards.
Every simulation starts with a question in your own words.

Meanwhile, the rest of us are asking:

  • What happens if I sign this lease?
  • Where should I park my food truck this week?
  • Where should our three pizza shops go so deliveries work on a busy Friday?
  • If they close the bridge for repairs, how long will my drive to work take?
  • If we open on Sundays, who would come?
  • How many hours of dangerous heat would we prevent by shading that bus stop?
  • Which storm drains on our block should we clear before the next downpour?
A model of homes, people and jobs open for editing in the dark look: a tray of parts, the stocks, flows, constants and computed quantities drawn as a diagram with the flows as pipes between the stocks, and a panel showing the equation of the selected flow.
A model written as stocks and flows, open for editing: the amounts that build up, the flows between them and the equation behind each flow. Change a piece, check the model and save it as a new draft.

Whathappensify is urban simulation for the rest of us. An AI you choose turns your question into a simulation. Whathappensify runs it, and the AI explains the result, what it means for your question and the evidence behind it. You see the work in your browser and direct what happens next.

The workbench in the light look: the setup's settings on the left, the map with the simulation area outlined in the middle, and the result panel on the right.
The workbench after a run: the setup with the settings you can change, the map with the simulation area outlined, and the result with the strength of the claim it supports.

Your AI assistant does the specialist work: finding suitable data and methods, preparing scenarios, running comparisons and interpreting the results. You can inspect its choices, change an assumption and pursue another possibility. Whose questions get explored should no longer depend on who can operate simulation software.

Rosa chooses a spot for her pupusa truck

Imagine Rosa choosing where to park her pupusa truck. The station is busy in the morning, but those commuters are hurrying to catch a train. Near another spot, people come out of their workplaces at lunch. A third spot is busiest when neighbors shop on the weekend. Which of these crowds is most likely to stop for pupusas?

What happens on a day when more people work from home? A spot that looks promising on a busy office day may do better or worse when the offices are half empty. Rosa can try another location or another day before she commits her time and ingredients.

One food truck. Three spots.Illustrated example · 72 seconds

01Three spots

Where should Rosa park her pupusa truck?

She has sold pupusas at a weekend market for years. Now she has a truck and three permitted spots to choose from.

Start with a question of your own.

Rosa's three permitted food-truck spots An illustrated neighborhood with a station corner, a square and a residential corner, with Rosa’s truck parked outdoors. A · Station cornerB · Near the squareC · Near homesOfficesNeighborhood square Three permitted spots

Three spots. One food truck. Different possibilities.

Try another permitted spot
0:00 / 1:12

Rosa is an imagined food-truck owner. This animation illustrates questions Whathappensify could help her explore.

About the illustration

The people and their movements are drawn for this explanation. The truck parks in three permitted spots, and the outdoor activity changes with the time and the work-from-home assumption. It illustrates how a question can develop; it is not a sales forecast or a recorded platform result.

Follow Rosa’s question · Read her imagined story

Follow the reasoning

CompositionTen operations give a hundred ordered pairs, self-pairs included. Fifteen fail the check.01CHECK02SEEK03MONITOR04IMAGINE05EXPLORE06COMPARE07EXPLAIN08GAUGE09CHOOSE10ADAPT
Ten ways an AI assistant can take your question further. The lines are the rules for which step may follow which; fifteen of the hundred are refused.

The Epistemic Protocol Machine, or EPM, lets an assistant take your question further and keeps a record of the evidence and assumptions behind each step. Rosa can ask why one spot looks promising, where the estimate of nearby customers came from, and how the choice changes on a quieter office day. The EPM keeps every answer within the limits of its evidence.

You can ask what produced a difference, which assumption mattered most, how strongly the evidence supports the result and what would change the conclusion. The record gives you a basis for examining the answer and taking the question further.

Explore the Epistemic Protocol Machine

From one moment to lasting change

A question can reach from the next few minutes to the next twenty years. A queue outside a clinic changes through the morning. Staff training, maintenance and investment change what that clinic can provide over years. Trees grow, infrastructure wears, people change their journeys, and today's choice changes tomorrow's conditions.

Whathappensify connects these processes in one experiment. Your assistant uses suitable physical and network models, draws on shared models or writes an inspectable model of the mechanism you want to explore. You approve the alternatives and scope, watch the work in your browser and follow how the consequences pass from one model to another.

The comparison shows which assumptions matter, how outcomes vary and who gains or loses. You can ask whether a conclusion survives a different assumption, which feedback produced a change, or what further observation could help you decide. Useful models, data and experience can be kept private or shared for others to build on.

Whose idea of better?

People can agree about a simulation result and care about different consequences. Rosa needs enough customers to sustain her business. Someone using a wheelchair needs room to reach the truck and order. A neighbor cares about customers blocking the sidewalk. Perspectives make those concerns explicit: what matters to someone, why it matters, and how the simulation represents it.

You can compare Perspectives, question a measure and propose a different definition of success. A concern stays on the record even when the model cannot express it as a number. You can examine both the reasoning and the purposes behind a comparison. People can work from shared evidence and still keep different priorities.

See one result through different Perspectives

One shade structure, three possible places

Leah helps look after a small town's public spaces. Her team has a modest budget and no simulation specialists. They can put up one shade structure before next summer. Where could it do the most good?

She asks her AI assistant to compare the library entrance, the public square and the playground. The busiest place changes through the day. So does the shade. And a place to wait comfortably can matter very differently to an older neighbor and to a family coming out after school.

One structure. Three public places.Illustrated example · 76 seconds

01A small town's choice

Where could a little shade do the most good?

Leah helps look after her town's public spaces. Her small team can put up one shade structure before next summer. She asks her AI assistant to compare three places.

A practical question. New possibilities.

Library entrance, public square and playground An imagined town with three public places where Leah could put a shade structure.

One structure could change how people use a public place.

Put the shade…
Look again…
What matters to…
0:00 / 1:16

Leah is an imagined town employee. This animation illustrates questions Whathappensify could help her explore.

About the illustration

The people, daily patterns and shade are drawn for this explanation. Choosing a different concern highlights people already in the scene. This is an illustration of a comparison, not a heat forecast or a recorded platform result.

Small towns make the same kinds of decisions as large cities, about bus routes, parking rules, opening hours and new services, usually without paying for a consultant's study. Accessible simulation could help a small team explore a choice, bring local knowledge into it and share the approach with another town. More people can shape the places where they live and work.

More people shaping what happens next

A prospective shopkeeper can compare locations before signing a lease. Neighbors can explore how to protect their building during a heat wave. As the climate changes, the people who live with the heat and the floodwater are often the first to see what could help. A volunteer can redesign a market so older shoppers can reach it. The questions, the local knowledge and the initiative come from people.

Explore more imagined uses · Grace prepares for a heat wave · Amara’s block keeps the rain out · Jamal’s tenants examine a rail proposal

You decide whether to keep your work private or share it. A market organizer could publish alternatives for traders and neighbors to explore through their own Perspectives. Someone else could make a fork, their own editable copy of the work, and try a different layout. An organizer across town could borrow the approach, using information about their own neighborhood.

Useful work can accumulate: simulations, prepared data, methods, Perspectives and experience that help the next person begin further along. People can return to what they explored, compare it with what actually happened and learn together.

Simulate back.

Democracy is how we decide our future. The power to explore possible futures should belong to all of us.

When a plan affects your home or livelihood, you should be able to examine its assumptions and develop an alternative of your own. If you disagree with a simulation someone has shared, change the assumption you dispute and explore what follows. Bring it to that hearing. Answer in kind. Residents, businesses and public servants can also use shared work to find a better arrangement while there is still time to shape it.

Nobody built this for us. We were never the customer. United Cities Foundation provides it as free, open-source public infrastructure, yours to examine and extend. People can initiate ideas, learn from one another and help decide what happens next.

How answering in kind could change a city

See the work

The dashboard in the dark look: the map on the left, the result card with its claim strength in the middle, and the list of recorded steps with their times on the right.
The dashboard: the map, the result with the strength of the claim it supports, and the record of each step with the time it happened.

Whathappensify connects simulation, AI assistants, reasoning that people can examine, and Perspectives that people can make their own. The screens show how you ask a question, examine a model, approve an experiment and explore its results. Open a screen to examine it more closely. One scenario can combine a physical model, a stock-and-flow model you write and network analysis over the same place.

The worked Perspective example shows how different points of view change what the same constructed result means. The technical reference explains the reasoning rules, calculations and detailed examples behind the design.

AI, simulation, the EPM, Perspectives and shared infrastructure serve one purpose: to let more people help decide what happens next.

Robert Kirkpatrick created Whathappensify and serves on the board of United Cities Foundation.

Read the full case · Examine the technical work · Contact Robert Kirkpatrick

Example platform views. Their values illustrate an analysis and are not findings about the places shown. Map data from OpenStreetMap. Map tiles: OpenFreeMap, © OpenMapTiles. Aerial imagery: USDA and USGS, The National Map. Terrain data courtesy of the U.S. Geological Survey.

Map data from OpenStreetMap. Map tiles: OpenFreeMap, © OpenMapTiles. Aerial imagery: USDA and USGS, The National Map. Terrain data courtesy of the U.S. Geological Survey.